Search results
Results from the WOW.Com Content Network
Many variations occur, but scintillating scotoma usually begins as a spot of flickering light near or in the center of the visual field, which prevents vision within the scotoma area. It typically affects both eyes, as it is not a problem specific to one eye. [5] [6] The affected area flickers but is not dark. It then gradually expands outward ...
Photopsia is the presence of perceived flashes of light in the field of vision. It is most commonly associated with: [4] posterior vitreous detachment. migraine aura ( ocular migraine / retinal migraine) migraine aura without headache. scintillating scotoma. retinal break or detachment.
Flicker vertigo, sometimes called the Bucha effect, is "an imbalance in brain-cell activity caused by exposure to low-frequency flickering (or flashing) of a relatively bright light." [ 1 ] It is a disorientation -, vertigo -, and nausea -inducing effect of a strobe light flashing at 1 Hz to 20 Hz, approximately the frequency of human brainwaves .
Uncommon (understudied) Visual snow syndrome ( VSS) is an uncommon neurological condition in which the primary symptom is that affected individuals see persistent flickering white, black, transparent, or colored dots across the whole visual field. [ 7][ 4] Other common symptoms are palinopsia, enhanced entoptic phenomena, photophobia, and ...
Specialty. Neurology. Frequency. 1 in 4000 [1] Photosensitive epilepsy ( PSE) is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights; bold, regular patterns; or regular moving patterns. PSE affects approximately one in 4,000 people (5% of those with epilepsy).
The flicker fusion threshold, also known as critical flicker frequency or flicker fusion rate, is the frequency at which a flickering light appears steady to the average human observer. It is a concept studied in vision science, more specifically in the psychophysics of visual perception. A traditional term for "flicker fusion" is "persistence ...
Eye closure in total darkness is ineffective. Contrary to other forms of photosensitive epilepsies that are sensitive only to flickering lights, patients with Jeavons syndrome are also sensitive to bright, non-flickering lights. This is probably due to the enhancing effect of bright light on the sensitivity of eye closure.
Flicker (light) In visual perception, flicker is a human-visible change in luminance of an illuminated surface or light source which can be due to fluctuations of the light source itself, or due to external causes such as due to rapid fluctuations in the voltage of the power supply ( power-line flicker) or incompatibility with an external dimmer.